View Full Version : Contrast ratios...


freakaftr8
01-26-2008, 08:11 PM
Hey guys I got a question, I dont wanna sound dumb and maybe I should already know this but...

I notice on our vintage sets that when you have a bright picture and black scenes in it as well, the whites really bleed down the darker images, it would actually look like I turned up the contrast to the max and turned down the brightness. then when it changes to a more neutral scene, it looks great again. I habe seen this on every vintage color tube set roundy or rectangular. Is this just old technology and there were better signal processing circuits in newer sets, or is it just me?

Thanks!

andy
01-26-2008, 09:40 PM
You're seeing poor DC restoration. Sets without good DC restoration will not hold a constant black level. A bright object in the picture will cause dark areas to become totally black, cutting off the shadow detail. Dark scenes will end up with gray instead of black. No one really did full DC restoration until the 70's. I think Sony was the first one to get it right. This is why Sony was known for great contrast compared to everyone else.

freakaftr8
01-27-2008, 12:35 PM
Oh thats what DC restoration is.. I found that sometimes you can tune this up a bit with the AGC. But if tuned too much the raster will become washed out and lack alot of contrast.